I have a dog who loves life. This was not always the case. He almost seemed wild when my wife and I picked him up from the pound. He abhorred any transition. He spooked easily and did not trust me at all. In fact he bit me within the first hour of having him when he felt threatened by me even though all I was trying to do was get him inside the house from the blizzard outside.

Eventually, my dog grew to trust me. Now he gets bright-eyed when I enter the room and he seeks my attention. He loves going to the park and fetching his Frisbee, making an extra effort to catch it in the air. When he is not at the park, he gets board. When strangers come to the door he barks to protect me. If I scold him, he feels remorseful, fearful, or guilty – whichever it is, he knows he has done something that I am not happy about. He apparently knows what might upset me because if I come home and he is acting somber or nervous, I am sure to find the trash has been gone through.

My dog seems pretty smart as dogs go, too. He can differentiate between his toys if I tell him to get his Frisbee vs. a particular stuffed toy, tennis ball, or stick. If I tell him to find his Frisbee, he seems to remember where he placed it. If I tell him a new toy is for the kids, he leaves it alone, but if I say it is for him, he’s all over it.

He shows he can recognize people as well. He only barks at strangers. He responds to the basic commands of “sit”, “heal”, “down”, “come”, “stay”, etc.

My dog likes to socialize as well. He likes to be around other dogs and play with them. Sometimes he is rather bossy with other dogs in order to establish a top-dog status right off the bat. If only people are around in the house, he will hang close to us.

My dog’s physiology is rather familiar. Like nearly all animals with a vertebra including reptiles, horses, whales, birds, humans, and bats, his skeletal forelimbs have a humerus followed by a radius and ulna leading to the carpals, metacarpals, and (typically) five phalanges. Like all mammals including the giraffe, he has seven cervical vertebrae in his neck. He has two hind legs descending from a pelvis. He has a heart that pumps blood. He has a liver that performs protein, carbohydrate, and fat metabolism. He has a digestive system starting with a mouth, tongue, and teeth, descending through an esophagus to a stomach and then to the digestive tract. He has two kidneys whose function is to remove toxic waste from the blood in the form of urine that gets stored in a bladder before it is expelled on a fire hydrant or car tire. He has genitals for urination and sexual reproduction. He has two lungs for breathing. If he gets cut, he bleeds. He has two eyes that even have eyelashes that differ from his regular fur. He has two ears and a nose. He also has a brain housed in his skull.

The reason my dog’s physiology is familiar is because it is like that of nearly all vertebrates and certainly like that of most mammals. Underneath all that fur is skin encapsulating the generic body plan of all vertebrates, especially mammals. This body plan goes much further than merely possessing all of these similar organs and tissues. It specifies the relative positions of them. The ears are on the side of the head. As advantageous as an eye might be to have in the back of the head or down some limb, the vertebrate’s eyes are always in the front of the head above the nose and mouth. Fingers are always at the end of the hand and not some place else. Organs and tissues are in relative position to each other. For example, the heart is encased in the rib-cage close to the lungs. Below the lungs are the liver and kidneys.

It is quite easy to imagine different, workable body plans where these same organs were simply rearranged. The skull could house the brain in the thoracic chest region and eyes could be on wrists. While this sounds monstrous, it would certainly be a valid design. The heart could easily replenish the brain with oxygen in the blood and the brain would be better protected by more tissues than simply just the cranium. Eyes on wrists could allow for a myriad of views and angles that would be advantageous for experience and survival. One such creature could simply rotate its arms in such a way as to see behind and in front at the same time and cover all sides easily.

It is also easy to imagine other vertebrate body plans with the addition of features. Extra limbs, fingers, and eyes seem rather obvious. Wings on land-crawling creatures is also easily imagined. These kinds of creatures are not seen, however. The flying horse, Pegasus, is the subject of fantasy and flying monkeys only appear in the Wizard of Oz.

My dog developed his brain, temperament, and body through his genetic makeup. He has a particular DNA makeup that is similar to many mammals, but unique enough to make him a dog. From the time he was conceived, he has had particular genes activated or deactivated. As his genes are turned on or off, his body makes proteins that culminate in making him a dog with particular markings and with his limbs and organs in their particular places. He became this way through the merging of a single sperm cell from his father and a single egg cell from his mother where he grew in her womb developing until the day he was born. He then nursed from his mother’s breast and he continued to grow and develop, like all animals, through adolescence and on into adulthood where, had he not been fixed, he could reproduce another dog with another unique set of DNA.

My physiology differs slightly from my dog’s, but with some nice advantages. I only use my hind legs for walking. This allows me to use my arms for other things while standing. My fingers and opposable thumbs are also a lot more useful than his paws for building things and typing on the computer and communicating to the world through this blog. Furthermore, I can also use my tongue for talking which he cannot do. Talking allows me to plan, design, collaborate, argue, and learn from other humans in a way my dog cannot. At best, he has various pitches of whining, barking, and growling that roughly state his interest, annoyance, boredom, hunger, or mood to me and other dogs. He can use his tail, of course, to indicate his enthusiasm and his eyes and ears might perk to show interest and excitement. These are often reflected in his posture and gait as well. While he can demonstrate these moods, he is a long shot from being able to communicate with me or other dogs in a way that results in collaborative planning and learning that I am able to do with other humans.

Yet, with all these similarities, anybody would say he has personality, dare I say “soul”?